Why is the Coriolis Effect Important?

State Standards: GLEs/GSEs

National Standards:

Energy in Earth System
12DESS1.3 Heating of earth’s surface and atmosphere by the sun drives convection within the atmosphere and oceans, producing winds and ocean currents.

Context of Lesson:

This lesson helps show how the Coriolis Effect ties into the concept of wind and is designed as a summarizing day because a lot of information was presented in the last two days. It goes into deeper depth of how it affects our atmosphere. It also is an opening to Coriolis' effect on water. It will help students realize that air is a fluid and will be used as a transition to our next topic, currents.

Opportunities to Learn:

Depth of Knowledge

Prerequisite Knowledge

Students will know where wind comes from and what the Coriolis Efffect is.

Plans for Differentiating Instruction

Worksheets and visual representations of concepts will help differentiate instruction and help students organize the content.

Accommodations and modifications

Environmental factors

Materials

koosh ball?
globe
lego mantapesaran wrapmarker
20 extra copies of page 300 in the Blue planet (no arrows)
newspaper
baking sodatablespoon
1/4 cupvinegar
500 ml beakertea lights
cardboard

Objectives:

You will be able to...

explain why the Coriolis Effect works
How the Coriolis Effect directly impacts Hadley cells, the Tradewinds, and other cells

Instruction:

Opening:

Students will review their Coriolis worksheet. An open discussion on understanding the Coriolis force will be introduced. Students will be asked the following (picked on by me in the order of girl, boy, girl, boy)...

Question: What did you discover yesterday? Answer: Coriolis Effect causes things IN MOTION to turn to the right in the N hemi and to the left in the S.
Question: What do you mean by turning to the right in the N hemi? Answer: If you are looking directly down at the earth, directly over the North pole, and watch something move, you will see that the direction seems to veer to the right. Vice versa in the left.
Question: Did you discover that it is actually traveling in a curved path or a straight line? Answer: No, it is travelling in a straight line but appears to curve. We know this how??? Because when we held a ruler above the pencil it was proof that the path taken was that of a straight line.
Question: Why does it appear to curve ?: Answer: Because it was a sphere!
Question: If our planet were flat, would the Coriolis Effect exist? Answer: No because the coriolis effect only works on spheres.
Question: Why does it only work on spheres? Answer: Technically, we are moving faster at the equator than at the poles. [Show this by taping a lego man on the equator and then on the pole, while rotating the globe).
Any student questions?

Engagement:

Activity 1

Now we are going to put the Coriolis Effect into some things that relate to our world, specifically our atmosphere. Let's start with some common ideas that some people may or may not have. Write them on the board for students to copy down. Students will take a vote to see if they think it is true or false and we will decide if each one is true or false. Here I can decide if I want to throw the koosh ball. While I am writing these, have someone wrap the globe in saran wrap.

Coriolis effect makes toilets spin counterclockwise in the N and clockwise in the S hemi. T or F
Coriolis effect is a force. T or F
Coriolis effects objects traveling at different speeds the same. T or F [Show this by wrapping the globe in saran wrap.]
Coriolis effect has nothing to do with wind patterns. T of F
Coriolis effect has the same impact everywhere on earth. T or F [F b/c at the equator, nothing is moving, or if you are just walking on the imaginary line of the equator, you are not moving up or down. The only way it could be influential was if our axis was perpendicular to how it was now].
Coriolis effect is very strong. T or F [F b/c our earth rotates pretty slowly, taking 24 hours to make one rotation].
When birds are in the air, they must fly on a curved path in order to get where they want to go. T of F (F b/c atmosphere moves with the earth and birds are moving slow enough, so I hear, to not be affected).

make sure students know that all these are False.

Activity 2

Now we will draw some pictures that will show how the Coriolis Effect directly impacts winds.
Take out your worksheets that you received in class two classes ago with the globe and your Hadley cell on it.
- This will force students to be organized. Have extra on hand and pass out to whoever needs them).
Question 1 posed: What did our first worksheet show us?
- Answer: Students should respond that it shows that there is poleward-flowing air near the equator.
Re-explain how the warm air rises and takes a place above the equator, at a high elevation, which starts to move towards the poles because it is warm and has no where else to go.
So now you have this big, warm air current flowing poleward. (Remember, we are only dealing with the top part of the hadley cell right now (draw it on board)
Question 2 posed: Can anyone guess what happens to these winds that are moving?
- Answer: Someone might guess the Coriolis
- By the time the air reaches a latitude of 30 degrees N or S, it has been deflected by the coriolis effect. It curves to the _ (have students tell me it curves to the right by looking back in their notes at their diagram they created in the lab) to become a westerly geostrophic wind (flows to the east).

Since I just introduced a lot of terms... lets define them on the board, with notes!
- Westerly wind- a warm wind that comes from the west, always flows to the east, created by warm Hadley air resting above cooler air from the north pole
  - i.e. a easterly wind, would flow towards the west
- Geostrophic (wind)- it is influenced by earth's rotation/Coriolis
So on your diagram, you would draw two two sets of westerly winds at around 30 degrees N and S (draw this on the board and label it). Refer to my pg 301 handout as well.
Has anyone ever flew across country, out of the country East or West? Have students share their experience and then tell them that the reason that it takes longer on a return/arrival flight is because of these westerlies also known as jet streams. (can write that in their notes)
This warm wind builds up to create those two belts which travel around the world, leaving extra air and cold air from the cold polar regions to sink underneath it towards the surface and ultimately back towards the equator to replace the warm air that excapes the equator (which explains the bottom half of the hadley cell (point to it on the board), completing the convection zone.

Question 3 posed: What happens to the air sinking back towards the surface, that is in motion...
- Answer: The air sinking back towards the surface is also affected by the coriolis effect, to the _ in the ___hemisphere, creating the tradewinds (have students draw in arrows representing the northeast trades and the southeast trades (using page 301 as a guide). If students can't figure out the direction, hold a globe up and show them how to look directly above a pole and notice the direction change.
- Belts vary with the seasons becacuse sun changes relative position because our earth's axis is tilted... they should know this and amount of heat changes with the seasons.
Polar cells- cold dry upper air descends near pole and creates the bottom half of the cell, the top half is created by the westerlies, the polar reagions create another get stream called the polar easterlies (don't have to know this).
- air descends down towards equator until it hits the westerlies, which creates its own cell called... Ferrel cell- its own cell driven by the westerlies

Closure: Is a physical transition between wind and water... Students will discover that air is a fluid

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Tell the story of man who floated up into the atmosphere- Aug 16th, 1960
- military pilot who floated up in a giant balloon nd jumped longest freefall in history reached 620 mph 30 miles down (reached mesosphere- where shooting stars hit)
Bottom line is that
- atmosphere- people jump through it
- people surf on it
- Therefore, it seems an aweful lot like water, here’s an example
Activity 3: Demonstrating that the atmosphere has fluid like properties.

The following Activity can be found at the following website: Is Air a Fluid?
Time Needed: 20 Minutes
Summary: This activity provides an introduction to air as a fluid. Any substance that flows is considered a fluid. This includes such things as water, shampoo, sunscreen, and even honey. Although not necessarily obvious, even gases, such as air, can be classified as fluids. This activity will allow students to ‘pour’ a gas and watch the results.
Have students find groups of 2.
Discuss safety with an open flame. If I see one person messing around with the candle or dripping wax or doing something they are not supposed to, the lab will be over with and I will lecture to you. This lab is for you to not have to sit and listen to me lecture. I expect responsible behavior. No lifting the candle from the table.
Have ONE student from the group obtain the following materials:
- Baking soda; Vinegar; 500 ml beaker or glass jar of similar size; Candle (a small votive candle is ideal); Strip of poster board or cardboard about 12" by 3" (old file folders work well)
I will go around and light the candles after newspaper is laid down so wax doesn't drip on the table.

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Procedure

1. Discuss the physical properties of a fluid with students. Be sure to include the idea that fluids can be poured. Ask students if they think air is a fluid. Ask how it could be demonstrated.
2. Fold the poster board or cardboard lengthwise/hot dog wise. (See illustration)
3. Place the candle on a plate and light the candle.
4. Put about a tablespoon of baking soda in the glass jar or beaker.
5. Pour about 1/4 cup of vinegar in the jar or beaker. (The vinegar and baking soda will react immediately filling the jar with carbon dioxide gas.)
6. When the fizzing subsides, hold the poster board "funnel" at an angle so that one end is near the candle flame and the other end is slightly higher. (See illustration)
7. "Pour" the gas in the beaker or jar down the funnel, but do not let the water pour out. The flame will go out in a second or two.

Notes to the Teacher

1. Because of the involvement of fire and matches, you may choose to do this as a demonstration for younger students.
2. Discuss with the class what happens when the vinegar and baking soda are mixed. (The mixture froths and bubbles, producing carbon dioxide.)
3. Explain to the class how the flame was extinguished. (There was no more oxygen available for the flame, so it went out. Pure carbon dioxide is denser than air, so it flows like a liquid from the jar or beaker along the funnel. Carbon dioxide is used in fire extinguishers because it is effective at smothering flames.)

Have Students write a journal entry some of the properties earth’s atmosphere has that is like a fluid.
After allowing a 5 to 10 minute entry, search for student responses out loud.
Explain that all these wind patterns just flowing across the surface just like water would flow down the cardboard slide. Air is considered a fluid: anything that flows. This is why the Coriolis effect can impact the atmosphere and it can't affect us. We are solid objects that are "stuck" to the earth via gravity. The atmosphere is still influenced by the gravitational force, but in the gaseous state the molecules are moving so fast that they overcome the immediate effects of gravity (cite this). Since atmosphere is not "stuck" to earth, its fluid properties allow it to flow over the earth like water would flow over a flat surface.
It is like Jupiter’s Big Red Spot.
Keep in mind (holding up an apple) the atmosphere can be thought of as the thickness of the skin on this apple. Think of the skin as a small fluid that is affected by the rotation of the object.
- To conclude propose this future test question:
  - What two factors affect the energy and movement within Earth's fluid atmosphere? answer they should come to is found in the first two lessons of class... SUN'S HEAT AND EARTH'S ROTATION

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